Wall retaining block



FIG. 1 is a front perspective view of the wall retaining block, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a side elevational view thereof, the other side being a mirror copy of this view;

FIG. 5 is a rear side elevational view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a wall retaining block, as shown and described. 